Accuton, C158-8-085

Accuton C158-8-085 6.25″ Ceramic Cone Mid/Bass

The  C158-8-085  is a 6.25-inch bass-midrange driver with an ultra-hard ceramic dome. An FEA optimized overhung motor design with 25 mm titanium voice coil former guarantees extraordinary low energy storage and good heat transfer. The low loss rubber surround and a  thin fabric spider center the moving parts with high linearity. As a typical small home stereo bass – midrange driver, we recommend our C158-8-085 for an application from 38 Hz – 3000 Hz.

This mid-woofer was chosen by Jim Holtz to use in his ultimate build, the “Bordeaux”   You can get the kit here or design your own.

• Overhung Motor Design
• Hybrid Ceramic/Neodymium Magnet System
• 25mm Titanium VC Former
• Soft Rubber Surround
• Vented VC, Pole Piece and Spider
• Imp – 8 Ohm
• Fs – 33Hz
• Qts – .31
• VAS – 35L
• SPL – 89dB
• Xmax – 5mm

Design considerations:

We wanted to create a bass-midrange driver for very compact two-way and – by the use of several units – slim three-way systems. So the C158-8-085 is a six-inch bass-midrange that offers some remarkable features:

We made it with the small 25mm voice coil of our C153- series but it has almost the membrane area of our C173- systems, which makes it superior in several ways.

We designed a unique suspension system to give it a high excursion capability with very low distortion. An egg-shaped soft rubber surround allows huge displacement without dragging the dome, supported by a new spider. It is made of “Bimax” tissue to advanced geometry, expanding the excursion limits to uncommon values as can be seen in the first picture. As we tried to determine the excursion limits of these units, we eventually burnt the voice coil but we never killed the ceramic cones.

The motor comes – first time with Accuton – as a hybrid system with both a ferrite and neodymium magnet, working in cooperation to achieve linearized BL(x) – and Inductance(x)-curves. This will guarantee a clear and un-distorted midrange quality even at high bass loads.

Stored energy was minimized by different means: we employed multiple venting techniques at the basket and the VC-former to avoid any compression effects and so could avoid the use of a vent hole in the yoke. A small titanium voice coil former with a lightweight VC takes very little mechanical and electromagnetic energy out of the system, ensuring an open and dynamic response.

C158-8-085 Data Sheet